Denmark has a unique tradition of combining power and heat production. By producing power and heat at the same time at DONG Energy’s power plants, we have achieved an efficiency of around 90 %. This makes our power plants cost-effective, and results in a high exploitation of the fuel’s energy content.

• Combined power and heat production
• District heating systems
• Increased efficiency

DONG Energy has a unique tradition of combining power and heat production. The surplus heat from power production is recycled in the district heating system, which supplies heating and hot water to Danish customers.

Exploitation of steam for heating
When the steam has released its energy to the turbine, which is used to produce power, it is used to heat cold district heating water in a heat exchanger. The district heating water is thus heated, and the steam cools and turns to water, which is then pumped back to the boiler where it is converted to high pressure steam.

District heating water is heated to approx. 100-120° C, and is then distributed to heating customers via district heating pipes. Part of the district heating water is stored in storage tanks, which can be drawn upon as required, as heat consumption varies according to seasons and time of day. 

Highly effective production
The higher the efficiency, the better the exploitation of the fuel and the fewer CO2 emissions per kWh produced. By producing power using methods that also generate heat, it is possible to exploit up to 90 % of the fuel's energy content.

In comparison, on a global scale coal-fired power plants that only produce power exploit just a third of their fuel content. DONG Energy’s modern coal-fired power plants, which only produce power, exploit 45 % of the fuel’s energy content.

Leading supplier
DONG Energy owns twelve central power plants, which stand for the majority of DONG Energy’s total power production. Eight of the twelve plants combine power and heat production. We have a further nine regional power plants that also combine power and heat production.
DONG Energy is the biggest producer of district heating in Denmark and supplies approx. 40 % of the heating on the market.